Examples of such an electronic device include a power meter, a gas meter, and a water meter having a communication function, which are called smart meters. Smart meters transmit the consumption of electric power, gas or water to the electric power companies, gas companies or water companies via networks. Servers send charges and the like to the smart meters. Furthermore, in order for the electric power companies to recognize the situation of occurrence of a power failure in a service area, the smart meters transmit power failure start time information and power failure recovery time information to the servers of the electric power companies. Since the smart meters is not equipped with batteries and are operated by the commercial power supply, the smart meters are not supplied with power and cannot conduct communication after a power failure occurs. To cope with this, the smart meter is provided with a large-capacity electric double-layer capacitor called a super-capacitor, charges the capacitor during operation with commercial power, and conducts communication using the power charged in the capacitor after occurrence of the power failure.
At occurrence of the power failure, however, since a large number of smart meters transmit the power failure occurrence time information to the server, each of the smart meters is considered to retry the communication many times due to communication errors. For this reason, some smart meters exhaust the charging power of the capacitors before completing the communication normally, and cannot notify the server of the power failure occurrence time information.
This problem may also arise at not only the smart meters, but also electronic devices which do not include batteries and are driven by a commercial power source and which need to notify external devices of the occurrence of a power failure.